Preventive services for adults: how have differences across subgroups changed over the past decade?

Background: A large literature documents cross-sectional differences in adult preventive services across population subgroups. Less is known, however, about how these differences have changed over time.
Objectives: This study tracks changes over time in the distribution of preventive services use across groups defined by poverty status, race/ethnicity, insurance coverage, Census region, and urbanicity.
Methods: Data from the 1996-2008 Medical Expenditure Panel Survey are used to examine 5 preventive services: general checkups, blood pressure screening, blood cholesterol screening, Pap smears, and mammograms. Multivariate logistic regression models of preventive services use are used to compute adjusted utilization for each subgroup of adults aged 19-64 in 1996/1998, 2002/2003, and 2007/2008. We then examine the extent to which percentage point gaps in utilization rates across subgroups have changed between 1996/1998 and 2007/2008.
Results: Our analysis of utilization rates across subgroups and over time identified only rare cases in which subgroup differences narrowed or widened between 1996/1998 and 2007/2008. Rather, differences across subgroups tended to persist over time. Some of the largest (adjusted) gaps are between adults with and without coverage, and only for blood cholesterol screening do we observe significant narrowing of the gap between the uninsured and the privately insured. Regional differences persisted or widened over the study period.
Conclusions: On the eve of health reform implementation, a key challenge facing the Affordable Care Act will be to address persistent differences in preventive services use within the US population.